One trek only: Machu Picchu or Colca Canyon?

I only have the time and the money for one 4day/3night trek during my visit next week. It would either be the Salkantay or Lares treks to Machu Picchu, or else something in the Colca Canyon.

If I you could only do one of these, which would it be?

I'm leaning towards the Colca Canyon, because I would think it has more to offer in terms of hiking and scenery, but I could be absolutely wrong. The other reason to go with the Colca Canyon is that a 4day trek into Machu Picchu might mean missing the Inti Raimi festival in Cusco. I might catch the last day...

Are there any major price differences between these two options? And who would you recommend as a tour group?

Thanks everyone!

24th is the day. If you cannot be there, watch it on TVPeru

i´ve done both and they are both great. but, the colca is slightly less touristy and probably cheaper. i did the colca canyon in 3 days/ 2 nights with a fantastic company, colca treks, from arequipa. in total, it cost $79 and that included all housing and food and transportation, plus a guide in english. it´s 240 soles to get into the MP park and that doesn´t include transportation back to cusco on the backpacker train, which is $45 one way. it´s more if you go for the vista dome, of course. if you want to do MP, then check out peru treks in cusco. i´m not sure if they do alternative treks, but you can at least talk to them. they are a great company and pay their porters more than most other companies.

I would say, go for the Inca Trail. We hiked the Colca Canyon too (independently), it was spectacular. But I would recommend the Inca Trail for the whole experience of it. The hike itself is very good, (very physically demanding in some parts), the scenery is very nice too, arriving to the sun gate early in the morning and watch the sun rise over Machu Picchu, (the setting around it even more spectacular then MP itself)! And then climb Waina Picchu (very bad idea for people who are afraid of heights!). The only downfall is that MP is much more expensive. We did the Inca Trail with the company called Llama Path. They are not the cheapest one around but they do look after they porters, make sure they don't carry very heavy loads, etc. The food was very good, each time we had the best spots in the campsites, the little things like warm water and a towel in front of your tent every morning and evening, the last dance with one of the porters (for ladies only!) on the last night, the cake on the last day, etc....Overall we were very happy with our choice.

Inca Trail. Without a doubt.